Two Halves Make A Whole
by foobar137
Summary: Doof's latest invention intermixes the essences of whatever it hits. What happens when it hits people? It turns out that intermixed souls don't like to be too far apart...Isabella and Phineas find this out the hard way. So do Vanessa and Perry. One-shot, Phinbella, a little Ferbnessa. Trope bingo: 'handcuffed/bound together'.


**Trope Bingo: handcuffed/bound together. Going for nonphysical bonds.**

**Timeframe: summer after the show; Phineas, Ferb, and Isabella are all about twelve, Vanessa is seventeen.**

* * *

Phineas and Ferb wandered into their backyard, looking around at the assembled kids. "Hey, folks. What'cha doin'?" Phineas asked.

Isabella smiled. "Waiting for you. How'd Perry's trip to the vet go?"

"Okay. He got a couple shots. Sorry we're getting a late start on inventing. It was a busy morning, with Candace going off with Dad to look at colleges."

Isabella looked around. "Hey, where is Perry, anyway?"

* * *

Heinz Doofenshmirtz sat in the chair next to his latest invention, impatiently waiting.

"Dad, why don't you just start working on your latest plan now instead of waiting for Perry?" his daughter Vanessa asked, without looking up from her magazine, from her position on the couch.

Heinz sighed. "Kids these days. No respect for tradition. Why, when I was a kid in Drusselstein, we didn't even have a nemesis to wait for, so we just had to wait forever before we did anything at all."

Vanessa rolled her eyes. "I know, and you had to walk to school through three feet of snow, uphill both ways."

"Exactly! Drusselstein is very tectonically active, so in the morning the school would be on top of a huge hill, but by afternoon it would be down in the bottom of a deep valley."

"Whatever."

A turquoise shape made a three-point landing on the balcony. Heinz turned to it. "Perry the Platypus! You're late. I should have just started without you, but aaaaanyway. So I was eating doonkleberry pancakes yesterday, and I got a seed stuck in my teeth. I hate that! And it occurred to me that what I want is to put the essense of doonkelberries into my pancakes without actually putting any berries in them.

"So, behold the Essence-Intermix-Inator! This little beauty will take the core essence of two things - kind of like their souls, I suppose - and mix them between the two things it hits. So if I put these doonkelberries next to these pancakes, and hit them with the Essense-Intermix-Inator...I get pancakes that taste like they've got doonkelberries in them, but without any seeds! And I get a bunch of doonkelberries that taste like they've got pancakes in them. I don't know what I'm going to do with those, they're not very useful."

Perry raised an eyebrow.

Heinz sighed. "Yes, I know, it's not really an _evil_ plan, but sometimes I just want to build an -inator recreationally, you know?"

Perry shrugged, and walked over to sit next to Vanessa. She looked up at him. "Hey, Perry. I'm sure Dad will go overboard with it eventually and you'll have to shut him down. Want a magazine to read while you wait?"

Perry shook his head, and looked over at Heinz. The evil scientist was swinging the -inator around, muttering something about intermixing coffee and bread to create toast that would wake you up in the morning. It suddenly went off, striking Perry and Vanessa with a blue beam.

Heinz looked up, "Oh, sorry about that. I don't _think_ it'll do anything serious to people. Or platypuses, for that matter." He pulled the -inator away from them and pointed it out the window, then leaned back on it, accidentally setting it off again.

* * *

Isabella and Phineas were looking through the book of Fireside Girl patches together, trying to figure out what patch to work on today, when a blue beam from above struck the pair. Phineas looked up. "That's weird. I wonder what that did."

Isabella shrugged. In her experience, random beams from the sky just happened, and, if they didn't cause immediate problems, weren't worth worrying about. "Here, I'll go grab the update book that has the latest patches." She stood up and was walking toward the table holding the book when suddenly a sudden pain struck her, a momentary agony like her heart was being ripped out of her chest. She cried out as she fell backwards, her voice blending with a similar shout from Phineas.

"What's wrong?" Gretchen asked her. "Are you okay, chief?"

Isabella looked back at Phineas, who was looking up at her with his eyes wide.

Phineas slowly leaned back, and she could feel the pain slowly building in her chest. His hand on his own chest, he leaned forward and the pain lessened.

He said, "Huh. I guess that's what that beam did. If we get more than...looks like about five feet apart from each other, it hurts. That's really weird."

* * *

Vanessa wandered over with Perry to the -inator as the platypus got ready to slap the self-destruct button.

Heinz was popping pancake-infused berries into his mouth. "Hey, these are actually pretty good," he said. "Want some?"

Vanessa shook her head and started to walk back to her magazine when her chest suddenly hurt, like an anchor in her rib cage was attached to something behind her. "Ow!" she yelled as Perry suddenly made a painful-sounding noise.

Heinz looked up. "Are you okay, Vanessa?" he asked with concern. "Did the mean old platypus hurt my baby girl?"

Perry chattered and glared at Heinz.

Vanessa shook her head. "No, it felt like...I suddenly got too far away from something important to me."

Perry walked over and took her hand, leading her toward the door.

"I think Perry has some idea what's going on. I'll call you and let you know what I find out, okay, Dad?"

"Take care of her, Perry. AHH! I got a seed stuck in my teeth! CURSE YOU, TASTY PANCAKE-INFUSED DOONKELBERRIES!"

* * *

Keeping Isabella close to him all the time, Phineas helped Ferb assemble the scanner. Ferb turned it on and stepped in front of it; it showed an outline of his body completely filled with green.

Baljeet looked at it. "So this scans...what again?"

"Souls," Ferb said. He gestured Phineas and Isabella over; scanning Phineas, the result showed his outline half-filled with red and half with pink. Isabella's looked similar.

Phineas said, "Huh. So that beam intermixed our souls? So we can't get too far away from each other, because the two halves of our souls can't be that far apart?"

Isabella said, "So I have to spend the rest of my life within five feet of Phineas?" Phineas looked at her; she didn't look especially upset about this idea.

Ferb said, "I'm sure there's some way to restore your souls." Isabella sighed and gave Ferb a disappointed look.

* * *

Vanessa followed Perry along the quiet residential street. The platypus paused, sighed, and looked up at her.

"What?" she asked.

He put a finger to his bill, indicating silence, then put one hand up as if swearing an oath.

"...you want me to be quiet about something?"

The platypus nodded.

"Are we near your home? Is that it? I can't tell my Dad where you live?"

Perry smiled and nodded.

"I owe you for not telling my Dad about Monty. I promise I won't tell him about this, okay?"

Perry held up his hand again, then two fingers.

"Second promise?"

Perry nodded, then rotated his hands to indicate switching positions. Vanessa cocked her head, puzzled. Perry sighed, put a finger to his bill, and pointed around him at the neighborhood.

Vanessa nodded. "And don't tell anybody here about how you fight my Dad. It's a deal."

Perry led her along to the gate leading to a back yard; he opened it, then jumped into her arms and took off his hat. She went in through the gate, surprised to see Ferb and Phineas and their friends.

Phineas looked up at her. "There you are, Perry! Where'd you find him, Vanessa?"

She thought quickly. "Um...downtown. We got hit by some blue beam, and now I can't get too far away from him. He led me back here."

"Really? That sounds like the blue beam that hit Isabella and me. If we get more than about five feet apart, it feels like something's trying to yank our hearts out. We found that our souls got mixed up a bit - half in each of us. Here, let's check the scanner and see if yours looks the same as ours."

Vanessa carried Perry over to the scanner; both outlines showed up, both half-filled with turquoise and half-filled with black.

"Yep, that looks the same," Phineas said. "We're still working on how to fix the problem. Any luck, Ferb?"

"I think so," the green-haired boy said. "I believe that continuous contact between you will help your souls migrate back to their proper bodies."

Isabella, smiling, reached over and grabbed Phineas's hand. He smiled, looking both pleased and a bit confused.

Vanessa looked down at Perry. "Looks like you're stuck with me for a while. Any guess how long it'll take, Ferb?"

"I'd estimate about twelve hours."

Phineas looked at Ferb, concerned. "But, Ferb...there aren't twelve hours before bedtime. And Isabella can't go back home without me until we get this fixed. Either she needs to sleep over here, or I need to sleep over there."

Isabella blushed.

Phineas snapped his fingers. "Ferb, I know what we're going to do tonight. How does everybody feel about a sleepover?"

* * *

Isabella watched as Phineas convinced his mother to go along with the sleepover, then got everyone's parents to agree as well. And throughout it all, he was holding her hand. His mother was distracted and didn't notice, fortunately. _Best day ever,_ she thought.

Phineas accompanied her over to her house for pajamas and toiletries. Her mother raised her eyes at the hand-holding; Isabella blushed but said nothing as they returned to the Fletcher-Flynn household.

* * *

Vanessa was trying to figure out how she was going to stay in contact with Perry all night when Linda suddenly bustled in. "Vanessa, I hate to do this to you, but I just got a call that my mother is sick. Is there any chance you can stay here until I get back? The kids are good, but I'd feel better to have someone of a responsible age here to keep an eye on them. It's likely to be quite late, possibly even tomorrow morning. I'll call your mother and clear it with her if you'd like."

Vanessa smiled. "I'll call my Dad; I'm with him this weekend anyway. I don't think it'll be a problem, though."

Linda sighed in relief. "Thank you so much. That makes me feel a lot better."

* * *

_Musical interlude: Isabella and Vanessa singing_

_Isabella:_ You've always had my heart  
And now half my soul as well  
Need to let you know my feelings  
But I'm far too scared to tell

_Vanessa:_ You fight my father daily  
Now I find I'm tied to you  
Just a stray -inator shot  
Now we're forced to be a two

_Isabella and Vanessa:_ Half of you and half of me  
Half of me and half of you  
Bound together by this link inside my soul

Half of you and half of me  
Half of me and half of you  
We're stuck together...because two halves make a whole.

* * *

Isabella had gone into the bathroom to change into her pajamas; Phineas stood outside the door, waiting. He thought about his feelings for her; he'd long suspected she liked him - really _liked_ him - but he had no idea what to do about it. Suddenly, he felt a pain in his chest, and heard Isabella's sharp intake of breath as the pain subsided.

"Um, Phineas..." she said through the door.

"Yes?"

"I need to go to the bathroom."

"Okay."

"The toilet is too far from the door. You need to come in."

Phineas gulped. "Are you decent?"

"I wouldn't have asked you to come in if I weren't."

Sighing, Phineas opened the door. Isabella was in her pajamas, waiting for him. "I'm sorry about this," he said.

She shrugged. "It's not your fault. Just don't peek."

He didn't. He was reasonably sure she didn't either when he used the bathroom as well.

* * *

Vanessa sat on the couch with Perry on her lap, idly stroking him. The kids were all watching a movie, mostly in sleeping bags on the living room floor. Phineas and Isabella were sitting next to each other on the couch, holding hands. Ferb was on the floor, leaning against the couch in the empty space between Isabella and Vanessa. The remnants of pizza boxes were scattered around the floor.

As she watched, Phineas pulled his hand from Isabella's. Isabella gave him a concerned look that rapidly changed to a bright smile as he instead put his arm around her shoulders. She shifted over to remove what little space had been between them. Vanessa shook her head and rolled her eyes.

She looked down at Ferb, who was looking over at Phineas and Isabella; she could only see the back of his head until he turned to look at her, then quickly looked away.

She shook her head. She knew Ferb had a crush on her - probably had ever since that first day at Blueprint Heaven, although she did now know that his silence was just the way he was and not that he was tongue-tied. She could see that he'd be a great catch in another few years, but not yet. However, it was nice to have _somebody_ interested in spending time with her. Since the blow-up with Monty, she'd been feeling unlovable; it was nice to know Ferb, at least, thought she was worthy of attention.

* * *

Phineas grabbed the remote and switched the TV over to a music station. Everyone else had gone to sleep during the last movie. Isabella was leaning on him and sound asleep, and he certainly didn't want to disturb her. Ferb had shifted up onto the couch to cuddle with Perry. (Phineas didn't think the fact that Perry was still on Vanessa's lap was entirely unrelated. He'd known about his little brother's crush for a while.)

He still didn't know quite what to do about Isabella's feelings for him, or his for her. But...she trusted him enough to fall asleep on him like this. Maybe he should trust her judgement here.

He leaned back into the corner of the couch, and she followed, pillowing her head on his shoulder. _I could get to like this_, he thought.

* * *

Linda returned home early the next morning. She was about to let people know she had returned when she saw the clusters of people sleeping on the couch.

Phineas was at one end of the couch, leaning up against the arm rest. Isabella was curled up against him, her head on his chest, looking completely content within his arms.

At the other end, Vanessa was lying against the back of the couch. Perry was resting on her lap, and next to her, Ferb was snugged up to her side with his arm around Perry.

_That's just adorable. I think, before I wake them up...I need to get pictures of this._

* * *

Phineas woke up slowly. Someone was lying on top of him. His eyes opened to black hair spread across his chest. His arms were around Isabella, who was still sleeping against him.

Out of the corner of his eye, he saw movement; his mother put her finger to her lips as she snapped pictures of the two of them together, and the pile of Vanessa, Perry, and Ferb at the other end of the couch.

The pictures taken, Mom put away the camera and said, "Who wants some breakfast?" Isabella startled awake, the sudden realization of where she was causing a concerned expression to cross her face. He gave her what he hoped was a tender smile; it seemed to work, because the concern faded as she took a deep breath, replaced by a shy smile as she sat up and stretched.

"Let's go check the scanner and see if it worked," he said. She took his hand as they slipped out the back door, unnoticed in the crowd of kids in the kitchen. The scanner came up and showed her outline entirely filled with pink and his completely red.

With a sigh, she started to pull her hand away, but he shook his head and didn't let go. "Just because we don't have to doesn't mean I don't want to," he said.

"Oh," she said, her eyes wide. The shy smile was back. "I think I want to too."

* * *

Vanessa and Perry's souls had both migrated back to their proper locations overnight as well. She stroked Perry's fur and said, "You've got a really nice family here, Perry. Take good care of them, okay?" He nodded, just a little.

She ruffled Ferb's hair and kissed him on the cheek, saying, "Thanks, Ferb," then headed back to her father's place.

Dad was lying on the floor, leaning on Norm, sleeping soundly and snoring loudly. Norm said loudly, "Hi, Sis. Welcome back. Dad and I got our souls mingled!"

Dad woke up and glared at Norm. "Who even knew you _had_ a soul? And I am not your father! Vanessa, can you do me a _huge_ favor, and go push the self-destruct button on that -inator? It's a little bit too dangerous to keep around."

* * *

**I think I'm just a sucker for "sleep cute".**

**Many thanks to 14AmyChan for drawing the crowd on the couch; the link's in my profile.**

**With this story I think I'm done with trope bingo for the year. Not sure what's coming next; I think I'm taking some time off to play BioShock Infinite, then working on one of the twelve (!) story ideas that's currently waiting for me. I'll be posting status reports at my Dreamwidth account; link is in my profile.**


End file.
